I am 14 years old.
When you want to say "umur saya 14 tahun" in English, you can simply say "I am 14 years old".
Here are some other ways to express the same idea:
- I am fourteen years old.
- My age is fourteen.
- I turned fourteen last [month/year].
- I am a fourteen-year-old.
The best way to say it depends on the context. For example, if you are filling out a form, you might say "My age is fourteen". If you are talking to a friend, you might say "I am fourteen years old".